SYNOPSIS

To push a new output level to the file ``foo.data'' (which will be
opened and closed automatically):

push_output('file','foo.data');

To push a new output level to a pipe to the shell command ``sort'':

push_output('pipe','sort');

To push a new output level appending to the file ``foo.data'':

push_output('append','foo.data');

To push a new output level to an empty string:

push_output('string');

To push a new output level appending to the string ``David is '':

push_output('string',"David is ");

To push a new output level to The Great Beyond:

push_output('nul');

To revert to the previous output level:

pop_output();

To revert to the previous output level, returning the contents of an
output string:

$data = pop_output();

DESCRIPTION

This library allows redirectable, stack-based output to files, pipes,
handles, strings, or nul. It is especially useful for packages like
SGMLS, since handlers for individual SGML elements can
temporarily change and restore the default output destination. It is
also particularly useful for capturing the contents of an element (and
its sub-elements) in a string.

AUTHOR AND COPYRIGHT

Copyright 1994 and 1995 by David Megginson,
"dmeggins@aix1.uottawa.ca". Distributed under the terms of the Gnu
General Public License (version 2, 1991) --- see the file "COPYING"
which is included in the SGMLS.pm distribution.